fs/xfs/scrub/scrub.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
   4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
   5  */
   6 #include "xfs.h"
   7 #include "xfs_fs.h"
   8 #include "xfs_shared.h"
   9 #include "xfs_format.h"
  10 #include "xfs_trans_resv.h"
  11 #include "xfs_mount.h"
  12 #include "xfs_log_format.h"
  13 #include "xfs_trans.h"
  14 #include "xfs_inode.h"
  15 #include "xfs_quota.h"
  16 #include "xfs_qm.h"
  17 #include "xfs_errortag.h"
  18 #include "xfs_error.h"
  19 #include "xfs_scrub.h"
  20 #include "scrub/scrub.h"
  21 #include "scrub/common.h"
  22 #include "scrub/trace.h"
  23 #include "scrub/repair.h"
  24 #include "scrub/health.h"
  25
  26 /*
  27  * Online Scrub and Repair
  28  *
  29  * Traditionally, XFS (the kernel driver) did not know how to check or
  30  * repair on-disk data structures.  That task was left to the xfs_check
  31  * and xfs_repair tools, both of which require taking the filesystem
  32  * offline for a thorough but time consuming examination.  Online
  33  * scrub & repair, on the other hand, enables us to check the metadata
  34  * for obvious errors while carefully stepping around the filesystem's
  35  * ongoing operations, locking rules, etc.
  36  *
  37  * Given that most XFS metadata consist of records stored in a btree,
  38  * most of the checking functions iterate the btree blocks themselves
  39  * looking for irregularities.  When a record block is encountered, each
  40  * record can be checked for obviously bad values.  Record values can
  41  * also be cross-referenced against other btrees to look for potential
  42  * misunderstandings between pieces of metadata.
  43  *
  44  * It is expected that the checkers responsible for per-AG metadata
  45  * structures will lock the AG headers (AGI, AGF, AGFL), iterate the
  46  * metadata structure, and perform any relevant cross-referencing before
  47  * unlocking the AG and returning the results to userspace.  These
  48  * scrubbers must not keep an AG locked for too long to avoid tying up
  49  * the block and inode allocators.
  50  *
  51  * Block maps and b-trees rooted in an inode present a special challenge
  52  * because they can involve extents from any AG.  The general scrubber
  53  * structure of lock -> check -> xref -> unlock still holds, but AG
  54  * locking order rules /must/ be obeyed to avoid deadlocks.  The
  55  * ordering rule, of course, is that we must lock in increasing AG
  56  * order.  Helper functions are provided to track which AG headers we've
  57  * already locked.  If we detect an imminent locking order violation, we
  58  * can signal a potential deadlock, in which case the scrubber can jump
  59  * out to the top level, lock all the AGs in order, and retry the scrub.
  60  *
  61  * For file data (directories, extended attributes, symlinks) scrub, we
  62  * can simply lock the inode and walk the data.  For btree data
  63  * (directories and attributes) we follow the same btree-scrubbing
  64  * strategy outlined previously to check the records.
  65  *
  66  * We use a bit of trickery with transactions to avoid buffer deadlocks
  67  * if there is a cycle in the metadata.  The basic problem is that
  68  * travelling down a btree involves locking the current buffer at each
  69  * tree level.  If a pointer should somehow point back to a buffer that
  70  * we've already examined, we will deadlock due to the second buffer
  71  * locking attempt.  Note however that grabbing a buffer in transaction
  72  * context links the locked buffer to the transaction.  If we try to
  73  * re-grab the buffer in the context of the same transaction, we avoid
  74  * the second lock attempt and continue.  Between the verifier and the
  75  * scrubber, something will notice that something is amiss and report
  76  * the corruption.  Therefore, each scrubber will allocate an empty
  77  * transaction, attach buffers to it, and cancel the transaction at the
  78  * end of the scrub run.  Cancelling a non-dirty transaction simply
  79  * unlocks the buffers.
  80  *
  81  * There are four pieces of data that scrub can communicate to
  82  * userspace.  The first is the error code (errno), which can be used to
  83  * communicate operational errors in performing the scrub.  There are
  84  * also three flags that can be set in the scrub context.  If the data
  85  * structure itself is corrupt, the CORRUPT flag will be set.  If
  86  * the metadata is correct but otherwise suboptimal, the PREEN flag
  87  * will be set.
  88  *
  89  * We perform secondary validation of filesystem metadata by
  90  * cross-referencing every record with all other available metadata.
  91  * For example, for block mapping extents, we verify that there are no
  92  * records in the free space and inode btrees corresponding to that
  93  * space extent and that there is a corresponding entry in the reverse
  94  * mapping btree.  Inconsistent metadata is noted by setting the
  95  * XCORRUPT flag; btree query function errors are noted by setting the
  96  * XFAIL flag and deleting the cursor to prevent further attempts to
  97  * cross-reference with a defective btree.
  98  *
  99  * If a piece of metadata proves corrupt or suboptimal, the userspace
 100  * program can ask the kernel to apply some tender loving care (TLC) to
 101  * the metadata object by setting the REPAIR flag and re-calling the
 102  * scrub ioctl.  "Corruption" is defined by metadata violating the
 103  * on-disk specification; operations cannot continue if the violation is
 104  * left untreated.  It is possible for XFS to continue if an object is
 105  * "suboptimal", however performance may be degraded.  Repairs are
 106  * usually performed by rebuilding the metadata entirely out of
 107  * redundant metadata.  Optimizing, on the other hand, can sometimes be
 108  * done without rebuilding entire structures.
 109  *
 110  * Generally speaking, the repair code has the following code structure:
 111  * Lock -> scrub -> repair -> commit -> re-lock -> re-scrub -> unlock.
 112  * The first check helps us figure out if we need to rebuild or simply
 113  * optimize the structure so that the rebuild knows what to do.  The
 114  * second check evaluates the completeness of the repair; that is what
 115  * is reported to userspace.
 116  *
 117  * A quick note on symbol prefixes:
 118  * - "xfs_" are general XFS symbols.
 119  * - "xchk_" are symbols related to metadata checking.
 120  * - "xrep_" are symbols related to metadata repair.
 121  * - "xfs_scrub_" are symbols that tie online fsck to the rest of XFS.
 122  */
 123
 124 /*
 125  * Scrub probe -- userspace uses this to probe if we're willing to scrub
 126  * or repair a given mountpoint.  This will be used by xfs_scrub to
 127  * probe the kernel's abilities to scrub (and repair) the metadata.  We
 128  * do this by validating the ioctl inputs from userspace, preparing the
 129  * filesystem for a scrub (or a repair) operation, and immediately
 130  * returning to userspace.  Userspace can use the returned errno and
 131  * structure state to decide (in broad terms) if scrub/repair are
 132  * supported by the running kernel.
 133  */
 134 static int
 135 xchk_probe(
 136         struct xfs_scrub        *sc)
 137 {
 138         int                     error = 0;
 139
 140         if (xchk_should_terminate(sc, &error))
 141                 return error;
 142
 143         return 0;
 144 }
 145
 146 /* Scrub setup and teardown */
 147
 148 /* Free all the resources and finish the transactions. */
 149 STATIC int
 150 xchk_teardown(
 151         struct xfs_scrub        *sc,
 152         int                     error)
 153 {
 154         struct xfs_inode        *ip_in = XFS_I(file_inode(sc->file));
 155
 156         xchk_ag_free(sc, &sc->sa);
 157         if (sc->tp) {
 158                 if (error == 0 && (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR))
 159                         error = xfs_trans_commit(sc->tp);
 160                 else
 161                         xfs_trans_cancel(sc->tp);
 162                 sc->tp = NULL;
 163         }
 164         if (sc->ip) {
 165                 if (sc->ilock_flags)
 166                         xfs_iunlock(sc->ip, sc->ilock_flags);
 167                 if (sc->ip != ip_in &&
 168                     !xfs_internal_inum(sc->mp, sc->ip->i_ino))
 169                         xfs_irele(sc->ip);
 170                 sc->ip = NULL;
 171         }
 172         if (sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR)
 173                 mnt_drop_write_file(sc->file);
 174         if (sc->flags & XCHK_REAPING_DISABLED)
 175                 xchk_start_reaping(sc);
 176         if (sc->flags & XCHK_HAS_QUOTAOFFLOCK) {
 177                 mutex_unlock(&sc->mp->m_quotainfo->qi_quotaofflock);
 178                 sc->flags &= ~XCHK_HAS_QUOTAOFFLOCK;
 179         }
 180         if (sc->buf) {
 181                 kmem_free(sc->buf);
 182                 sc->buf = NULL;
 183         }
 184         return error;
 185 }
 186
 187 /* Scrubbing dispatch. */
 188
 189 static const struct xchk_meta_ops meta_scrub_ops[] = {
 190         [XFS_SCRUB_TYPE_PROBE] = {      /* ioctl presence test */
 191                 .type   = ST_NONE,
 192                 .setup  = xchk_setup_fs,
 193                 .scrub  = xchk_probe,
 194                 .repair = xrep_probe,
 195         },
 196         [XFS_SCRUB_TYPE_SB] = {         /* superblock */
 197                 .type   = ST_PERAG,
 198                 .setup  = xchk_setup_fs,
 199                 .scrub  = xchk_superblock,
 200                 .repair = xrep_superblock,
 201         },
 202         [XFS_SCRUB_TYPE_AGF] = {        /* agf */
 203                 .type   = ST_PERAG,
 204                 .setup  = xchk_setup_fs,
 205                 .scrub  = xchk_agf,
 206                 .repair = xrep_agf,
 207         },
 208         [XFS_SCRUB_TYPE_AGFL]= {        /* agfl */
 209                 .type   = ST_PERAG,
 210                 .setup  = xchk_setup_fs,
 211                 .scrub  = xchk_agfl,
 212                 .repair = xrep_agfl,
 213         },
 214         [XFS_SCRUB_TYPE_AGI] = {        /* agi */
 215                 .type   = ST_PERAG,
 216                 .setup  = xchk_setup_fs,
 217                 .scrub  = xchk_agi,
 218                 .repair = xrep_agi,
 219         },
 220         [XFS_SCRUB_TYPE_BNOBT] = {      /* bnobt */
 221                 .type   = ST_PERAG,
 222                 .setup  = xchk_setup_ag_allocbt,
 223                 .scrub  = xchk_bnobt,
 224                 .repair = xrep_notsupported,
 225         },
 226         [XFS_SCRUB_TYPE_CNTBT] = {      /* cntbt */
 227                 .type   = ST_PERAG,
 228                 .setup  = xchk_setup_ag_allocbt,
 229                 .scrub  = xchk_cntbt,
 230                 .repair = xrep_notsupported,
 231         },
 232         [XFS_SCRUB_TYPE_INOBT] = {      /* inobt */
 233                 .type   = ST_PERAG,
 234                 .setup  = xchk_setup_ag_iallocbt,
 235                 .scrub  = xchk_inobt,
 236                 .repair = xrep_notsupported,
 237         },
 238         [XFS_SCRUB_TYPE_FINOBT] = {     /* finobt */
 239                 .type   = ST_PERAG,
 240                 .setup  = xchk_setup_ag_iallocbt,
 241                 .scrub  = xchk_finobt,
 242                 .has    = xfs_sb_version_hasfinobt,
 243                 .repair = xrep_notsupported,
 244         },
 245         [XFS_SCRUB_TYPE_RMAPBT] = {     /* rmapbt */
 246                 .type   = ST_PERAG,
 247                 .setup  = xchk_setup_ag_rmapbt,
 248                 .scrub  = xchk_rmapbt,
 249                 .has    = xfs_sb_version_hasrmapbt,
 250                 .repair = xrep_notsupported,
 251         },
 252         [XFS_SCRUB_TYPE_REFCNTBT] = {   /* refcountbt */
 253                 .type   = ST_PERAG,
 254                 .setup  = xchk_setup_ag_refcountbt,
 255                 .scrub  = xchk_refcountbt,
 256                 .has    = xfs_sb_version_hasreflink,
 257                 .repair = xrep_notsupported,
 258         },
 259         [XFS_SCRUB_TYPE_INODE] = {      /* inode record */
 260                 .type   = ST_INODE,
 261                 .setup  = xchk_setup_inode,
 262                 .scrub  = xchk_inode,
 263                 .repair = xrep_notsupported,
 264         },
 265         [XFS_SCRUB_TYPE_BMBTD] = {      /* inode data fork */
 266                 .type   = ST_INODE,
 267                 .setup  = xchk_setup_inode_bmap,
 268                 .scrub  = xchk_bmap_data,
 269                 .repair = xrep_notsupported,
 270         },
 271         [XFS_SCRUB_TYPE_BMBTA] = {      /* inode attr fork */
 272                 .type   = ST_INODE,
 273                 .setup  = xchk_setup_inode_bmap,
 274                 .scrub  = xchk_bmap_attr,
 275                 .repair = xrep_notsupported,
 276         },
 277         [XFS_SCRUB_TYPE_BMBTC] = {      /* inode CoW fork */
 278                 .type   = ST_INODE,
 279                 .setup  = xchk_setup_inode_bmap,
 280                 .scrub  = xchk_bmap_cow,
 281                 .repair = xrep_notsupported,
 282         },
 283         [XFS_SCRUB_TYPE_DIR] = {        /* directory */
 284                 .type   = ST_INODE,
 285                 .setup  = xchk_setup_directory,
 286                 .scrub  = xchk_directory,
 287                 .repair = xrep_notsupported,
 288         },
 289         [XFS_SCRUB_TYPE_XATTR] = {      /* extended attributes */
 290                 .type   = ST_INODE,
 291                 .setup  = xchk_setup_xattr,
 292                 .scrub  = xchk_xattr,
 293                 .repair = xrep_notsupported,
 294         },
 295         [XFS_SCRUB_TYPE_SYMLINK] = {    /* symbolic link */
 296                 .type   = ST_INODE,
 297                 .setup  = xchk_setup_symlink,
 298                 .scrub  = xchk_symlink,
 299                 .repair = xrep_notsupported,
 300         },
 301         [XFS_SCRUB_TYPE_PARENT] = {     /* parent pointers */
 302                 .type   = ST_INODE,
 303                 .setup  = xchk_setup_parent,
 304                 .scrub  = xchk_parent,
 305                 .repair = xrep_notsupported,
 306         },
 307         [XFS_SCRUB_TYPE_RTBITMAP] = {   /* realtime bitmap */
 308                 .type   = ST_FS,
 309                 .setup  = xchk_setup_rt,
 310                 .scrub  = xchk_rtbitmap,
 311                 .has    = xfs_sb_version_hasrealtime,
 312                 .repair = xrep_notsupported,
 313         },
 314         [XFS_SCRUB_TYPE_RTSUM] = {      /* realtime summary */
 315                 .type   = ST_FS,
 316                 .setup  = xchk_setup_rt,
 317                 .scrub  = xchk_rtsummary,
 318                 .has    = xfs_sb_version_hasrealtime,
 319                 .repair = xrep_notsupported,
 320         },
 321         [XFS_SCRUB_TYPE_UQUOTA] = {     /* user quota */
 322                 .type   = ST_FS,
 323                 .setup  = xchk_setup_quota,
 324                 .scrub  = xchk_quota,
 325                 .repair = xrep_notsupported,
 326         },
 327         [XFS_SCRUB_TYPE_GQUOTA] = {     /* group quota */
 328                 .type   = ST_FS,
 329                 .setup  = xchk_setup_quota,
 330                 .scrub  = xchk_quota,
 331                 .repair = xrep_notsupported,
 332         },
 333         [XFS_SCRUB_TYPE_PQUOTA] = {     /* project quota */
 334                 .type   = ST_FS,
 335                 .setup  = xchk_setup_quota,
 336                 .scrub  = xchk_quota,
 337                 .repair = xrep_notsupported,
 338         },
 339         [XFS_SCRUB_TYPE_FSCOUNTERS] = { /* fs summary counters */
 340                 .type   = ST_FS,
 341                 .setup  = xchk_setup_fscounters,
 342                 .scrub  = xchk_fscounters,
 343                 .repair = xrep_notsupported,
 344         },
 345 };
 346
 347 /* This isn't a stable feature, warn once per day. */
 348 static inline void
 349 xchk_experimental_warning(
 350         struct xfs_mount        *mp)
 351 {
 352         static struct ratelimit_state scrub_warning = RATELIMIT_STATE_INIT(
 353                         "xchk_warning", 86400 * HZ, 1);
 354         ratelimit_set_flags(&scrub_warning, RATELIMIT_MSG_ON_RELEASE);
 355
 356         if (__ratelimit(&scrub_warning))
 357                 xfs_alert(mp,
 358 "EXPERIMENTAL online scrub feature in use. Use at your own risk!");
 359 }
 360
 361 static int
 362 xchk_validate_inputs(
 363         struct xfs_mount                *mp,
 364         struct xfs_scrub_metadata       *sm)
 365 {
 366         int                             error;
 367         const struct xchk_meta_ops      *ops;
 368
 369         error = -EINVAL;
 370         /* Check our inputs. */
 371         sm->sm_flags &= ~XFS_SCRUB_FLAGS_OUT;
 372         if (sm->sm_flags & ~XFS_SCRUB_FLAGS_IN)
 373                 goto out;
 374         /* sm_reserved[] must be zero */
 375         if (memchr_inv(sm->sm_reserved, 0, sizeof(sm->sm_reserved)))
 376                 goto out;
 377
 378         error = -ENOENT;
 379         /* Do we know about this type of metadata? */
 380         if (sm->sm_type >= XFS_SCRUB_TYPE_NR)
 381                 goto out;
 382         ops = &meta_scrub_ops[sm->sm_type];
 383         if (ops->setup == NULL || ops->scrub == NULL)
 384                 goto out;
 385         /* Does this fs even support this type of metadata? */
 386         if (ops->has && !ops->has(&mp->m_sb))
 387                 goto out;
 388
 389         error = -EINVAL;
 390         /* restricting fields must be appropriate for type */
 391         switch (ops->type) {
 392         case ST_NONE:
 393         case ST_FS:
 394                 if (sm->sm_ino || sm->sm_gen || sm->sm_agno)
 395                         goto out;
 396                 break;
 397         case ST_PERAG:
 398                 if (sm->sm_ino || sm->sm_gen ||
 399                     sm->sm_agno >= mp->m_sb.sb_agcount)
 400                         goto out;
 401                 break;
 402         case ST_INODE:
 403                 if (sm->sm_agno || (sm->sm_gen && !sm->sm_ino))
 404                         goto out;
 405                 break;
 406         default:
 407                 goto out;
 408         }
 409
 410         /*
 411          * We only want to repair read-write v5+ filesystems.  Defer the check
 412          * for ops->repair until after our scrub confirms that we need to
 413          * perform repairs so that we avoid failing due to not supporting
 414          * repairing an object that doesn't need repairs.
 415          */
 416         if (sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) {
 417                 error = -EOPNOTSUPP;
 418                 if (!xfs_sb_version_hascrc(&mp->m_sb))
 419                         goto out;
 420
 421                 error = -EROFS;
 422                 if (mp->m_flags & XFS_MOUNT_RDONLY)
 423                         goto out;
 424         }
 425
 426         error = 0;
 427 out:
 428         return error;
 429 }
 430
 431 #ifdef CONFIG_XFS_ONLINE_REPAIR
 432 static inline void xchk_postmortem(struct xfs_scrub *sc)
 433 {
 434         /*
 435          * Userspace asked us to repair something, we repaired it, rescanned
 436          * it, and the rescan says it's still broken.  Scream about this in
 437          * the system logs.
 438          */
 439         if ((sc->sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
 440             (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 441                                  XFS_SCRUB_OFLAG_XCORRUPT)))
 442                 xrep_failure(sc->mp);
 443 }
 444 #else
 445 static inline void xchk_postmortem(struct xfs_scrub *sc)
 446 {
 447         /*
 448          * Userspace asked us to scrub something, it's broken, and we have no
 449          * way of fixing it.  Scream in the logs.
 450          */
 451         if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 452                                 XFS_SCRUB_OFLAG_XCORRUPT))
 453                 xfs_alert_ratelimited(sc->mp,
 454                                 "Corruption detected during scrub.");
 455 }
 456 #endif /* CONFIG_XFS_ONLINE_REPAIR */
 457
 458 /* Dispatch metadata scrubbing. */
 459 int
 460 xfs_scrub_metadata(
 461         struct file                     *file,
 462         struct xfs_scrub_metadata       *sm)
 463 {
 464         struct xfs_scrub                sc = {
 465                 .file                   = file,
 466                 .sm                     = sm,
 467                 .sa                     = {
 468                         .agno           = NULLAGNUMBER,
 469                 },
 470         };
 471         struct xfs_mount                *mp = XFS_I(file_inode(file))->i_mount;
 472         int                             error = 0;
 473
 474         sc.mp = mp;
 475
 476         BUILD_BUG_ON(sizeof(meta_scrub_ops) !=
 477                 (sizeof(struct xchk_meta_ops) * XFS_SCRUB_TYPE_NR));
 478
 479         trace_xchk_start(XFS_I(file_inode(file)), sm, error);
 480
 481         /* Forbidden if we are shut down or mounted norecovery. */
 482         error = -ESHUTDOWN;
 483         if (XFS_FORCED_SHUTDOWN(mp))
 484                 goto out;
 485         error = -ENOTRECOVERABLE;
 486         if (mp->m_flags & XFS_MOUNT_NORECOVERY)
 487                 goto out;
 488
 489         error = xchk_validate_inputs(mp, sm);
 490         if (error)
 491                 goto out;
 492
 493         xchk_experimental_warning(mp);
 494
 495         sc.ops = &meta_scrub_ops[sm->sm_type];
 496         sc.sick_mask = xchk_health_mask_for_scrub_type(sm->sm_type);
 497 retry_op:
 498         /*
 499          * When repairs are allowed, prevent freezing or readonly remount while
 500          * scrub is running with a real transaction.
 501          */
 502         if (sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) {
 503                 error = mnt_want_write_file(sc.file);
 504                 if (error)
 505                         goto out;
 506         }
 507
 508         /* Set up for the operation. */
 509         error = sc.ops->setup(&sc);
 510         if (error)
 511                 goto out_teardown;
 512
 513         /* Scrub for errors. */
 514         error = sc.ops->scrub(&sc);
 515         if (!(sc.flags & XCHK_TRY_HARDER) && error == -EDEADLOCK) {
 516                 /*
 517                  * Scrubbers return -EDEADLOCK to mean 'try harder'.
 518                  * Tear down everything we hold, then set up again with
 519                  * preparation for worst-case scenarios.
 520                  */
 521                 error = xchk_teardown(&sc, 0);
 522                 if (error)
 523                         goto out;
 524                 sc.flags |= XCHK_TRY_HARDER;
 525                 goto retry_op;
 526         } else if (error || (sm->sm_flags & XFS_SCRUB_OFLAG_INCOMPLETE))
 527                 goto out_teardown;
 528
 529         xchk_update_health(&sc);
 530
 531         if ((sc.sm->sm_flags & XFS_SCRUB_IFLAG_REPAIR) &&
 532             !(sc.flags & XREP_ALREADY_FIXED)) {
 533                 bool needs_fix;
 534
 535                 /* Let debug users force us into the repair routines. */
 536                 if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_FORCE_SCRUB_REPAIR))
 537                         sc.sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
 538
 539                 needs_fix = (sc.sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
 540                                                 XFS_SCRUB_OFLAG_XCORRUPT |
 541                                                 XFS_SCRUB_OFLAG_PREEN));
 542                 /*
 543                  * If userspace asked for a repair but it wasn't necessary,
 544                  * report that back to userspace.
 545                  */
 546                 if (!needs_fix) {
 547                         sc.sm->sm_flags |= XFS_SCRUB_OFLAG_NO_REPAIR_NEEDED;
 548                         goto out_nofix;
 549                 }
 550
 551                 /*
 552                  * If it's broken, userspace wants us to fix it, and we haven't
 553                  * already tried to fix it, then attempt a repair.
 554                  */
 555                 error = xrep_attempt(&sc);
 556                 if (error == -EAGAIN) {
 557                         /*
 558                          * Either the repair function succeeded or it couldn't
 559                          * get all the resources it needs; either way, we go
 560                          * back to the beginning and call the scrub function.
 561                          */
 562                         error = xchk_teardown(&sc, 0);
 563                         if (error) {
 564                                 xrep_failure(mp);
 565                                 goto out;
 566                         }
 567                         goto retry_op;
 568                 }
 569         }
 570
 571 out_nofix:
 572         xchk_postmortem(&sc);
 573 out_teardown:
 574         error = xchk_teardown(&sc, error);
 575 out:
 576         trace_xchk_done(XFS_I(file_inode(file)), sm, error);
 577         if (error == -EFSCORRUPTED || error == -EFSBADCRC) {
 578                 sm->sm_flags |= XFS_SCRUB_OFLAG_CORRUPT;
 579                 error = 0;
 580         }
 581         return error;
 582 }